Electrical shocks when Powerbook G4 is plugged in.

Now I noticed that, when the powerbook is plugged in, the case seems to carry some electrical current.
markus wrote on :

Hi all,

I got a new Powerbook G4 15" 1,67 GHz and it already needed 2 repairs (motherboard + trackpad button).

Now I noticed that, when the powerbook is plugged in, the case seems to carry some electrical current. If I sweep my hands over the aluminium enclosure my hand tingles sligthly. It stops at the moment when I unplug the power adapter.

Apple says this is normal.

Somehow I cant believe this - there are a lot of electric household items with metallic casings and they never "tingle".

Does anybody experience the same phenomenon?

Regards markus

gutts replied on :

markus webmaster@redacted.invalid wrote:

Does anybody experience the same phenomenon?

yes, on a much older pbook g4 800 MHz

David M. Wood replied on :

markus webmaster@redacted.invalid wrote:

If I sweep my hands over the aluminium enclosure my hand tingles sligthly. It stops at the moment when I unplug the power adapter.

Apple says this is normal.

Somehow I cant believe this - there are a lot of electric household items with metallic casings and they never "tingle".

Does anybody experience the same phenomenon?

Absolutely! On a 12" 1.33 GHz Powerbook; now that I'm back in the US it seems to me that it's MUCH more noticeable running in Europe off 240 V than off the 120 V here. I agree--most unexpected.

Jose Marques replied on :

On Wed, 27 Apr 2005, markus wrote:

Does anybody experience the same phenomenon?

Yes, it's static electricty. The PB's is a metal case on insulated feet is ideal for collecting charge. It's harmless.

DaveC replied on :

On Thu, 28 Apr 2005 03:16:55 -0700, Jose Marques wrote (in article Pine.OSX.4.61.0504281113560.15523@redacted.invalid):

Yes, it's static electricty.

Not accurate, but the charge is not harmful. Static electricity is a charge generated from non-electronic components (car seats, cheap suits, cat's fur).

Hallvard Tangeraas replied on :

David M. Wood wrote:

markus webmaster@redacted.invalid wrote:

Does anybody experience the same phenomenon?

Absolutely! On a 12" 1.33 GHz Powerbook; now that I'm back in the US it seems to me that it's MUCH more noticeable running in Europe off 240 V than off the 120 V here. I agree--most unexpected.

I'm going to buy a Powerbook later this year, but this has got me worried! I really hate getting zapped by static electricity, but this sounds even worse. I'll be afraid of touching the computer! There must be an electrical fault somewhere! It's not supposed to be like this, is it? If so, there's got to be something that can be done about it.

PS. the entire European continent isn't 240V -that's mostly the UK as far as I know. The rest is 220 or 230V.

John Johnson replied on :

In article 4271641e$1@redacted.invalid, Hallvard Tangeraas inv@redacted.invalid wrote:

David M. Wood wrote:

markus webmaster@redacted.invalid wrote:

Does anybody experience the same phenomenon?

Absolutely! On a 12" 1.33 GHz Powerbook; now that I'm back in the US it seems to me that it's MUCH more noticeable running in Europe off 240 V than off the 120 V here. I agree--most unexpected.

I'm going to buy a Powerbook later this year, but this has got me worried! I really hate getting zapped by static electricity, but this sounds even worse. I'll be afraid of touching the computer! There must be an electrical fault somewhere!

In some sense, yes. However, on a machine showing this phenomenon there may not be any obvious fault with any component, or obvious electrical connection to the case (e.g. stripped/broken insulation on a fan or or screen wire).

It's not supposed to be like this, is it? No, and AFAIK most machines don't. My 15" PB does not, and none of my collegues' (I know 6-7 users directly) PowerBooks do it. I have heard (here, mostly) of a couple of isolated reports like the above since the TiBook was released (first metal-case PB, as I recall).

If so, there's got to be something that can be done about it.

Again, in some sense there must be. However, figuring out what that is, and convincing someone else to pay for it, can be difficult. In Europe (I know this to be the case in the UK, and similar legislation exists elsewhere in the EU) you are likely to be covered by a law that allows you to return an item without justification. Just plug the thing in and see whether it makes you tingle. If so, back it goes. If you're not covered by such a guarantee, well...most PowerBooks don't do this. HTH

Hallvard Tangeraas replied on :

John Johnson wrote:

Just plug the thing in and see whether it makes you tingle. If so, back it goes. If you're not covered by such a guarantee, well...most PowerBooks don't do this. HTH

Good to hear that this isn't something common to all G4 Powerbooks as I would be reconsidering my purchase, looking at the iBook instead. I would certainly return a Powerbook if it caused me to get a shock every time I touch it!

Out of curiosity, does anyone know exactly how many volts we're talking about? It should be a simple matter of using a multimeter/voltmeter, connecting one probe to the chassis and the other one to ground (e.g. a grounded electrical socket).

John Johnson replied on :

In article 4271e807$1@redacted.invalid, Hallvard Tangeraas inv@redacted.invalid wrote:

John Johnson wrote:

Just plug the thing in and see whether it makes you tingle. If so, back it goes. If you're not covered by such a guarantee, well...most PowerBooks don't do this. HTH

Good to hear that this isn't something common to all G4 Powerbooks as I would be reconsidering my purchase, looking at the iBook instead. I would certainly return a Powerbook if it caused me to get a shock every time I touch it!

Out of curiosity, does anyone know exactly how many volts we're talking about? It should be a simple matter of using a multimeter/voltmeter, connecting one probe to the chassis and the other one to ground (e.g. a grounded electrical socket).

It's going to depend on what exactly is providing the voltage. Voltage into the PB is 24.5, DC. However, the screen inverter both increases the voltage and changes it to AC for the backlight. There's lots of other voltages present in the computer, any of which could leak to the case for one reason or another.

That said, you should be able to measure the voltage with a good multi-meter, from the case to whatever you are grounded to (not an electrical socket, I hope). The problem with using an electrical socket as a ground is that it may be floating a couple or even tens of volts above 0, typically as a result of bleed from other portions of your house wiring, but possibly also because whatever your ground wires run to is floating. Unfortunately for you, whatever surface you are standing on may not be a good enough ground for your meter to register a voltage. A human being is a pretty good detector of voltage, so low-quality meters might not give consistent readings even when you feel something. Did I mention that this sort of thing is often non-obvious? ;-)

When I worked in the theatre, the sound guys would go nuts trying to trace down ground-loops, feedback, and 'buzz' in their audio systems. It's about as bad as SCSI voodoo, but with much longer cable runs and much higher voltages and Amperages. And in the hall where I spent most of my time, they had isolated power so didn't have to worry about bleed from our lighting equipment or other sources. Your house almost certainly doesn't have that advantage, though a dual-conversion UPS helps out a lot.

Hallvard Tangeraas replied on :

John Johnson wrote:

In article 4271e807$1@redacted.invalid, Hallvard Tangeraas inv@redacted.invalid wrote:

Out of curiosity, does anyone know exactly how many volts we're talking about?

It's going to depend on what exactly is providing the voltage. Voltage into the PB is 24.5, DC. However, the screen inverter both increases the voltage and changes it to AC for the backlight. There's lots of other voltages present in the computer, any of which could leak to the case for one reason or another.

Inverters... they could increase the voltage quite a lot. As far as I remember from messing around with similar stuff we're talking hundreds of volts, but with a very low current. Bad enough to give you a tingle, but usually quite harmless.

And in the hall where I spent most of my time, they had isolated power so didn't have to worry about bleed from our lighting equipment or other sources. Your house almost certainly doesn't have that advantage, though a dual-conversion UPS helps out a lot.

We also have to keep in mind that this is for a laptop, meaning that for many people it'll be used in a lot of different locations with different electrical standards. I'm certainly not interested in buying a computer that's going to give me a shock/tingle all the time. I would call that a defect and ask for a replacement or refund.

The question is if this is something Apple can get away with and not allow me to get a replacement/refund, or if it is indeed a factory defect? If I can risk getting a "shockable" Powerbook, and it can't be replaced I'm going to consider getting an iBook instead as they have plastic cases as far as I remember.

According to one of the rumour pages (http://www.appleinsider.com/article.php?id=1014) the iBook is going to be updated for higher speed and memory specs etc. so perhaps that's not such a bad option. Another issue with the Powerbook is apparently that it makes a lot more noise than the iBook. But I really don't know -I haven't used either, but reading a lot of posts with these complaints doesn't make the Powerbook sound too appealing unfortunately. But who knows -perhaps a lot of them are wrong, exaggerated, or just unlucky, defective machines.

John Johnson replied on :

In article 42728209@redacted.invalid, Hallvard Tangeraas inv@redacted.invalid wrote:

John Johnson wrote:

[snip]

I'm certainly not interested in buying a computer that's going to give me a shock/tingle all the time. I would call that a defect and ask for a replacement or refund.

The question is if this is something Apple can get away with and not allow me to get a replacement/refund, or if it is indeed a factory defect?

The ease with which you can return a PowerBook with this sort of symptoms varies widely by jurisdiction. I don't know your local consumer protection laws, so I can't really tell you more. Here in the USA it can be quite difficult indeed to get such an item replaced unless Apple (or other company involved) agrees: there is typically (though even here it varies by jurisdiction-there's no federal standard) no requirement that they replace the 'Book if they deem it to be operating 'normally', whatever that means. And if Apple claims that it's operating normally you have to go to an awful lot of trouble to prove otherwise. In the worst case scenario it would be far cheaper and easier to simply purchase another PowerBook rather than collect evidence of the problem and fight it out in courts.

If I can risk getting a "shockable" Powerbook, and it can't be replaced I'm going to consider getting an iBook instead as they have plastic cases as far as I remember.

According to one of the rumour pages (http://www.appleinsider.com/article.php?id=1014) the iBook is going to be updated for higher speed and memory specs etc. so perhaps that's not such a bad option. Another issue with the Powerbook is apparently that it makes a lot more noise than the iBook.

My PowerBook is quiet and 'tingle' free. IME, it's the 12" PB that gets the most complaints about being noisy, and this is not much of a surpise. It's the 12" PB that is also most similar to the iBook, making it a better candidate for substitution. In my case, I really wanted the capabilities of the PowerBook (I do presentations fairly regularly, use monitor spanning regularly, and use the extra width of the 15" screen all the time), and particularly the 15" (that extra width), so the iBook made less sense.

But I really don't know -I haven't used either, but reading a lot of posts with these complaints doesn't make the Powerbook sound too appealing unfortunately. But who knows -perhaps a lot of them are wrong, exaggerated, or just unlucky, defective machines.

Remember, people without problems don't typically post about their lack of problems. People with problems often do. While PowerBooks have had their share of difficulties, so have iBooks (video cable and logic board most notably), and other brands of computers as well. There are a number of ways of protecting yourself from difficulties:

  1. it is often recommended to purchase from a reseller who allows one to open up the item before purchase if possible (typically not possible with CPU purchases).
  2. purchase from a reseller who allows returns for arbitrary reasons, even if Apple does not.
  3. Know your local consumer protection legislation: even if Apple does not accept returns for arbitrary reasons (in general), they may be forced to by local legislation. The UK has a quite strong law in this respect: any item may be returned in the first 14 days if the purchaser determines that it is 'unfit' for its use. That's how I understand it, at any rate (UK residents feel free to correct me).
  4. Get an extended warranty. I recommend AppleCare (where available) to all purchasers of Apple's portables. A portable computer leads a much rougher life than a desktop, and its design (everything is smaller, closer together, hotter, etc.) stresses components more. IMO, the peace of mind is worth quite a bit, even if actual problems are not encountered. That said, Apple may not be the cheapest place to purchase such an agreement (again, if it's available where you live).

There's more here: some credit-card purchases are covered by special, consumer-friendly, terms, you can get 3rd party extended warrranties, etc. In addition, I don't mean to imply that problems are likely. In fact I believe the opposite: Apple makes very good equipment and IME problems are rare and usually minor. Yes, some people have serious problems, and some have serious recurring problems (at least one person here had their iBook replaced after Apple had attempted to repair it multiple times), but these are the exceptional cases. If you are one of the unlucky ones though, there are things to do that can mitigate the severity of the problem.

Ok, I think we've covered this one in about as much detail as possible. The options are pretty clear and it's up to Hallvard to make the decision, based on all available information. Get back here if you've got other questions, otherwise happy days!

Tom replied on :

markus wrote:

Hi all,

I got a new Powerbook G4 15" 1,67 GHz and it already needed 2 repairs (motherboard + trackpad button).

Now I noticed that, when the powerbook is plugged in, the case seems to carry some electrical current. If I sweep my hands over the aluminium enclosure my hand tingles sligthly. It stops at the moment when I unplug the power adapter.

Apple says this is normal.

Somehow I cant believe this - there are a lot of electric household items with metallic casings and they never "tingle".

Does anybody experience the same phenomenon?

Regards markus

Are you using the correct power adapter? The 65W ones with a silver pin have an earth connection whereas earlier ones with a plastic pin and yoyo shaped ones do not.

If you are using the correct one with the sliver pin, does the wall socket adapter you are using connect that pin to earth, or are just the live an neutral connected?

There is 100 ohm resistance between the pin and the 0V side of the PSU that is connected to the Powerbook case, so if the pin is earthed any static build up on the case would be dissipated to earth.

DaveC replied on :

On Fri, 29 Apr 2005 14:39:35 -0700, John Johnson wrote (in article null-96CBBC.16393429042005@redacted.invalid):

Remember, people without problems don't typically post about their lack of problems. People with problems often do.

The old adage (paraphrasing): "A person with a bad experience tells 10; one with a good experience tells 1"

DaveC replied on :

On Sat, 30 Apr 2005 06:19:19 -0700, Tom wrote (in article 427385D7.24FF5683@redacted.invalid):

Are you using the correct power adapter? The 65W ones with a silver pin have an earth connection whereas earlier ones with a plastic pin and yoyo shaped ones do not.

This is a very good and important question. Marcus? Which adapter are you using?

markus replied on :

Hi all,

I got a new Powerbook G4 15" 1,67 GHz and it already needed 2 repairs (motherboard + trackpad button).

Now I noticed that, when the powerbook is plugged in, the case seems to carry some electrical current. If I sweep my hands over the aluminium enclosure my hand tingles sligthly. It stops at the moment when I unplug the power adapter.

Apple says this is normal.

Somehow I cant believe this - there are a lot of electric household items with metallic casings and they never "tingle".

Does anybody experience the same phenomenon?

Regards markus

Are you using the correct power adapter? The 65W ones with a silver pin have an earth connection whereas earlier ones with a plastic pin and yoyo shaped ones do not.

If you are using the correct one with the sliver pin, does the wall socket adapter you are using connect that pin to earth, or are just the live an neutral connected?

There is 100 ohm resistance between the pin and the 0V side of the PSU that is connected to the Powerbook case, so if the pin is earthed any static build up on the case would be dissipated to earth.

I am using the correct power adapter, which came with my powerbook

  • a little square white brick. However at least in Germany we get two plugs with the power adapter. One thick round plug with extension cord and an earth connection and one flat plug without extension cord and without earth connection. The flat one is a lot lighter and is a standard euro plug - which can be used all over europe, so it is the one I carry around.

The effect can only be noticed when using the flat adapter. This seems to be the case because of the missing grounding, but I am still think this should not happen, since there are a lot of electrical household items which do not exhibit this problem.

Howevere Apple seems to know about this problem and says this is the standard behaviour.

Does anybody NOT experience the same phenomenon when using a flat plug without grounding?

Hallvard Tangeraas replied on :

markus wrote:

Howevere Apple seems to know about this problem and says this is the standard behaviour.

I'm in Norway and would be using the same plug as you if I decide to buy a Powerbook. Where did you hear/read that Apple says this is standard behaviour of the PowerBook G4? Is this an official statement from them?

I've always hated getting static electrical shocks (frequent in winter when the air is dry), so I dread to think about getting shocks every time I put my hands on the Powerbook.

How on earth can this be acceptable and "normal" for a computer? Is the chassis of the Powerbook somehow connected to a "live" electrical component? If so, why would Apple do this? Just so Powerbook users could "get a shock" out of using their "electrifying machines"? ;-) Joke aside, I think it sucks if Apple claims this to be "OK" and "normal", and do nothing about it. I've never heard about anything similar with PC laptops.

Jose Marques replied on :

On Thu, 28 Apr 2005, DaveC wrote:

Not accurate, but the charge is not harmful. Static electricity is a charge generated from non-electronic components (car seats, cheap suits, cat's fur).

I've expreienced shocks from a 12" PB and it's very much like the static shock you get when touching a metal object in a room with cheap carpets and dry air. As I said the 12" PB makes an ideal collector for static electricity generated by other means. I've also experience a shock from 240V mains (I was wiring up an extension cable which was plugged in) and that is very much different.

John Johnson replied on :

In article b11506ab.0505030041.5bf7ca2f@redacted.invalid, webmaster@redacted.invalid (markus) wrote:

Hi all,

I got a new Powerbook G4 15" 1,67 GHz and it already needed 2 repairs (motherboard + trackpad button).

Now I noticed that, when the powerbook is plugged in, the case seems to carry some electrical current. If I sweep my hands over the aluminium enclosure my hand tingles sligthly. It stops at the moment when I unplug the power adapter.

Apple says this is normal.

Somehow I cant believe this - there are a lot of electric household items with metallic casings and they never "tingle".

Does anybody experience the same phenomenon?

Regards markus

Are you using the correct power adapter? The 65W ones with a silver pin have an earth connection whereas earlier ones with a plastic pin and yoyo shaped ones do not.

If you are using the correct one with the sliver pin, does the wall socket adapter you are using connect that pin to earth, or are just the live an neutral connected?

There is 100 ohm resistance between the pin and the 0V side of the PSU that is connected to the Powerbook case, so if the pin is earthed any static build up on the case would be dissipated to earth.

I am using the correct power adapter, which came with my powerbook

  • a little square white brick. However at least in Germany we get two plugs with the power adapter. One thick round plug with extension cord and an earth connection and one flat plug without extension cord and without earth connection. The flat one is a lot lighter and is a standard euro plug - which can be used all over europe, so it is the one I carry around.

The effect can only be noticed when using the flat adapter.

Ok, that's pretty much it, then. It's also not that much of a surprise. As for kitchen appliances, the vast majority of ungrounded appliances in my part of the USA have plastic or plastic-covered cases. Your PowerBook has a bare metal case.

Howevere Apple seems to know about this problem and says this is the standard behaviour.

This also isn't a surprise, and implies that the issue is voltage build-up as a result of induction with the case or leakage. It's rather likely to be static electricity, but you'd have to actually meter it to know.

Does anybody NOT experience the same phenomenon when using a flat plug without grounding?

AFAIK, my PowerBook does not do this. Nope, nothing. This may not tell us much though: I've got my power adapter plugged into a fairly nice UPS, so if the issue is caused by 'dirty' power (unlikely but possible) it wouldn't show up here. You might try connecting your PowerBook to different outlets and see whether the behaviour is present all the time.

I'll say it again: AFAIK, this sort of behaviour is uncommon. AFAIK the only way to tell whether it's going to happen is to try out the machine, and doing away with the behaviour on a machine that is experiencing it is likely to be far more frustrating than carrying around the grounded connector unless it's as simple as changing power outlets (which indicates 'dirty' power). It's mixed news, but that's what I know, so far as I know it.

Tim Smith replied on :

In article 427385D7.24FF5683@redacted.invalid, Tom no@redacted.invalid wrote:

Are you using the correct power adapter? The 65W ones with a silver pin have an earth connection whereas earlier ones with a plastic pin and yoyo shaped ones do not.

If you are using the correct one with the sliver pin, does the wall socket adapter you are using connect that pin to earth, or are just the live an neutral connected?

There is 100 ohm resistance between the pin and the 0V side of the PSU that is connected to the Powerbook case, so if the pin is earthed any static build up on the case would be dissipated to earth.

The power brick Apple ships with the current PowerBooks has a two-prong plug, not a three-prong plug, so won't be grounded when used in the out-of-the-box configuration.

The plug is detachable, and there is an extension cord that is included that can be used instead of the default plug. That cord does have a three-pronged plug on it.